Presidential Green Chemistry Challenge: 2009 Designing Greener Chemicals Award
The Procter & Gamble Company
Cook Composites and Polymers Company (Chempol® technology acquired by Arkema Coating Resins)
Chempol® MPS Resins and Sefose® Sucrose Esters Enable High-Performance Low-VOC Alkyd Paints and Coatings
Innovation and Benefits: Conventional oil-based "alkyd" paints provide durable, high-gloss coatings but use hazardous solvents. Procter & Gamble and Cook Composites and Polymers are developing innovative Chempol® MPS paint formulations using biobased Sefose® oils to replace petroleum-based solvents. Sefose® oils, made from sugar and vegetable oil, enable new high-performance alkyd paints with less than half the solvent. Paints with less hazardous solvent will help improve worker safety, reduce fumes indoors as the paint dries, and improve air quality.
Summary of Technology: Solvent-borne alkyd coatings are in demand because they are cost-effective and high-performing in many applications including architectural finishes, industrial metal, and equipment for agriculture and construction. Millions of gallons of these paints and coatings are sold in the United States and around the world. Conventional alkyd resin paints and coatings require large amounts of volatile solvents to solubilize the organic components and attain appropriate viscosities. These solvents contribute to the formation of ground-level ozone and smog. Low-VOC alkyd coatings exist, but suffer from inferior performance. Some take too long to dry; others use substitute, VOC-exempt solvents that tend to be expensive and often have an undesired odor or other inferior performance. Low-VOC, waterborne acrylic latex paints are also available, but they have performance trade-offs such as low gloss and reduced corrosion resistance compared to solvent-borne alkyd coatings.
The Procter & Gamble Company (P&G) and Cook Composites and Polymers Company (CCP) have collaborated to develop a new alkyd resin technology that enables formulation of paints and coatings with less than half the VOCs of solvent-borne alkyd coatings. These alkyd formulations are enabled by Sefose® sucrose esters, which are prepared from renewable feedstocks by esterifying sucrose with fatty acids in a patented, solventless process. The molecular architecture and functional density of Sefose® are controlled by selecting natural oil feedstocks with optimal fatty acid chain length distribution, unsaturation level, and degree of esterification. In applied paint films, Sefose® undergoes auto-oxidative cross-linking with other constituents and becomes an integral part of the coating films. Chempol® MPS alkyd resins are specially formulated to deliver performance advantages such as fast drying, high gloss, film toughness, and increased renewable content.
Replacement of conventional alkyd resins by Chempol® MPS could (1) reduce VOCs equivalent to the emissions from 7,000,000 cars per year; (2) reduce ground-level ozone by 215,000 tons per year; and (3) save 900,000 barrels per year of crude oil from the solvents and alkyd polymers it replaces. Chempol® MPS is cost-competitive with conventional alkyds on an equal-dry-film basis. In October 2008, CCP launched Chempol® MPS and began actively sampling the coatings industry. P&G is also evaluating and testing Sefose® oils as biobased alternatives to replace petroleum-based lubricants.
Podcast on the technology:
2009 Designing Greener Chemicals Award podcast (mp3) (MP3, 1.3 MB, 1:27 minutes)